Site Preformance is a part of Google Webmaster Tools, where it is still classified as experimental. The tool tracks how fast your pages load, and how that has changed over time. The goal is to bring webmasters “specific and actionable speed information backed by data,” to get their sites flying.

Recall that speed might come into play in your websites search rankings on the search giant.

The interface of the service looks like this, image via Google:

Google collects the data from people using the Google Toolbar, and have opted into the enhanced features toolset. It might feel a touch big-brother, but the data should be priceless to the major publication. If you are not sure how your site preforms, especially over slower connections, this tool might just be a godsend.

Google wants you to get using the tool right away, and provide feedback here.